CPW fed 2 × 2 patch array for D-band System-in-Package applications

A 2×2-patch array for System-in-Package radar sensors at 122 GHz is presented in this paper. The antenna is realized on a 127 μm thick Alumina substrate and fed by a coplanar-waveguide (cpw) which allows direct attachment to a monolithic millimeter-wave integrated circuit (MMIC) as well as a probe-based measurement of the antenna. The design of the microstrip-fed patch array itself and the cpw-to-microstrip transition are explained. Measured results of gain, radiation pattern and return loss are presented, showing good agreement to simulation.